Fatigue modeling

Hursh SR, Redmond DP, Johnson ML, Thome DR, Belenky G, Balkin TJ, Storm WF, Miller JC, Eddy DR. Fatigue models for applied research in warfighting. Aviat Space Environ Med. In press. 

Multiscale Fatigue Modeling Example of Automotive Corvette Cradle... 

Figure 4.9 illustrates the multistage fatigue model s calibrated predictions for different types of inclusions illustrating the various length scales involved. It is to be noted that the final number of cycles decreases with increasing level of inclusion severity. 

Fig. 4.9 Multistage fatigue model results illustrating the different length scale inclusions that...

Fig. 4.10 Uniaxial strain-life experiments and multistage fatigue model predictions for AE44 specimens with predicted upper and lower bounds...

Fig. 4.11 Corvette cradle modeling and simulation results from the internal state variable plasticity-damage model coupled with the multistage fatigue model demonstrating the capability to predict the experimental result for redesigning the cradle from aluminum to magnesium...

M. F. Horstemeyer et al., From Atoms to Autos Part 2 Fatigue Modeling, Sandia National Laboratories Report, SAND2001-8.661 (2001). 

D.L. McDowell et al Microstructure-based fatigue modeling of cast A356-T6 alloy. Eng. Fracture Mech. 70, 49-80 (2003)... 

Y. Xue et al Multistage fatigue modeling of cast A356-T6 and A380-F aluminum alloys. Metall. Matls. Trans. 38B 601-606 (2007)... 

Y. Xue et al Microstructure-based multistage fatigue modeling of aluminum alloy 7,075-T651. Eng. Fract. Mech. 74, 2810-2823 (2007)... 

According to the power law fatigue model, the safe allowable stress for a converter... 

The power-law fatigue model [26,27] helps estimate the safe allowable regeneration stress for a specified filter life. Denoting the filter s short-term modulus of rupture by 52, the safe allowable stress Si is given by... 

The wear rate-load data for the modified epoxies have load exponents less than one. Several fatigue models for wear predict that the exponent should be greater than one ( ). Explanation for... 

For the slloxane modified epoxies and the polylmides, the wear rates correlated positively with the elastic moduli, which is also in agreement with the fatigue model. However, the wear rate-load relationship predicted by fatigue models was not corroborated by the data. Likewise, the effect of load on the cycles to initiate for the polylmides was not consistent with the fatigue model. 

The positive correlation of wear rates with elastic moduli E of the polylmides is consistent with the fatigue model for wear ( ). The reason for this correlation is that the surfaces stresses which are calculated using the Hertzian contact equations are proportional to Higher stresses lead to high wear rates because less stress cycles are required to cause a fatigue failure and produce a wear particle. 

Figure 7. Bowed crack front and process zone in mode I fatigue modeling.

Stoeckl, Stephan, Yeo, Alfred, Lee, Charles, and Pape, Heinz, Impact of Fatigue Modeling on 2d Level Joint Reliability of EGA Packages with SnAgCu Solder Bails, Electronics Packaging Technology Conference,2005, pp. 857-862. 

W. Lee, L. Nguyen, and G. Selvaduray, Solder Joint Fatigue Models Review and Applicability to Chip Scale Packages, Microelectronics Reliability, Vol 40,2000, p 231-244... 

K. Tunga, J. Pyland, R.V. Pucha, and S.K. Sitaraman, Study on the Choice of Constitutive and Fatigue Models in Solder Joint Life Prediction, Proceedings of IMECE 2002... 

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